In science education, the use of laboratory experiments has a critical role. However, experiments can cause excessive material waste, and safety issues must be taken seriously. Virtual laboratories and simulations have become a useful and effective alternative to in-person, hands-on laboratories as a result of the educational possibilities afforded by information and communication technology. With virtual reality (VR), students can depict scientific phenomena through virtual practical experiments that use computer simulation. In this work, VR-based lab simulations of physics and chemistry experiments were introduced. Chemistry lab includes 3 experiments from organic chemistry (identify aldehydes using Tollen's test, identify ketones using the 2,4-dinitrophenyl hydrazine test, and identify carboxylic acids using the sodium carbonate test) and physics lab includes 2 experiments on series and parallel current, accomplished through the use of the real-time 3D graphics and pre-rendered animations. Further, to assess the usability of the developed system, 20 students were surveyed as research subjects and they filled out the SUS survey after conducting the VR experiments in Oculus Quest 2. . The average score for the VR chemistry lab simulations was 92.63%, and, the average score for the physics lab was 93.38%, indicating a high level of performance and achievement among the participants. Further, in the comparative study evaluating knowledge retention and learning experience, the experimental group (VR, N=20) outperformed the control group (traditional, N=13), indicating a more favorable learning experience. All participants from the experiment group reported that virtual labs were easy to use. Overall, findings from the Knowledge Retention survey show that interactive laboratory activities enhance students' understanding of chemical processes and practical skills.